Brock was walking Pee Wee, a small, high-strung West Highland terrier who darted into the brush at the slightest provocation — a sudden breeze, shifting gravel, a tour bus rumbling down Caffin Avenue several blocks east. But Pee Wee had reason to be anxious. Brock was anxious. Most residents of the Lower Ninth Ward in New Orleans are anxious. “A lot of people in my little area died after Katrina,” Brock said. “Because of too much stress.” The most immediate sources of stress that October morning were the stray Rottweilers. Brock had seen packs of them in the wildly overgrown lots, prowling for food. Pee Wee, it seemed, had seen them, too. “I know they used to be pets because they are beautiful animals.” Brock corrected herself: “They were beautiful animals. When I first saw them, they were nice and clean — inside-the-house animals. But now they just look sad.”

The Lower Ninth has become a dumping ground for unwanted dogs and cats. People from all over the city take the Claiborne Avenue Bridge over the Industrial Canal, bounce along the fractured streets until they reach a suitably empty area and then toss the animals out of the car. But it’s not just pets. The neighborhood has become a dumping ground for many kinds of unwanted things. Contractors, rather than drive to the city dump in New Orleans East, sweep trailers full of construction debris onto the street. Auto shops, rather than pay the tire-disposal fee ($2 a tire), dump tires by the dozen. The tire problem has become so desperate that the city is debating changes to the law. (One humble suggestion: a $2 reward per tire.) You also see burned piles of household garbage, cotton-candy-pink tufts of insulation foam, turquoise PVC pipes, sodden couches tumescing like sea sponges and abandoned cars. Sometimes the cars contain bodies. In August, the police discovered an incinerated corpse in a white Dodge Charger that was left in the middle of an abandoned lot near the intersection of Choctaw and Law, two blocks from where Mary Brock was walking Pee Wee. Nobody knew how long the car had been there; it was concealed from the closest house, half a block away, by 12-foot-high grass. That entire stretch of Choctaw Street, for that matter, was no longer visible. It had been devoured by forest. Every housing plot on both sides of the street for two blocks, between Rocheblave and Law, was abandoned. Through the weeds, you could just make out a cross marking the spot where Brock’s neighbor had drowned.

It is misleading to talk about abandoned lots in the context of the Lower Ninth Ward. Vast sections of the neighborhood have been abandoned, so it’s often unclear where one property ends and the next begins. (An exception is the sliver of land on the neighborhood’s innermost edge, where Brad Pitt’s Make It Right Foundation has built 76 solar-paneled, pastel-hued homes — though this seems less a part of the neighborhood than a Special Economic Zone.) To visualize how the Lower Ninth looked in September — before the city’s most recent campaign to reclaim the neighborhood — you have to understand that it no longer resembled an urban, or even suburban environment. Where once there stood orderly rows of single-family homes with driveways and front yards, there was jungle. The vegetation had all sprouted since Katrina. Trees that did not exist before the storm are now 30 feet high.

The cartoonish pace of vegetation growth resembles something out of a Chia Pet commercial, but it is hardly surprising to New Orleanians long accustomed to roads warped by tree roots and yards invaded by weeds. The soil in the Lower Ninth is extraordinarily fertile, thanks to centuries of alluvial deposits from the Mississippi River, which forms the neighborhood’s southern boundary. From the river, the neighborhood descends, like a long ramp, down to an open-water, brackish marsh called Bayou Bienvenue. This back part of the neighborhood, which, at its lowest point, is four feet below sea level, was the most devastated by the storm and remains the least inhabited. Its population has decreased by 85 percent since 2000.

Many of the ruined buildings have been cleared away, and most of the old foundations are obscured. The inhabited lots, about one per city block, are the exception. With their dutifully trimmed lawns, upright fences and new construction, they stand out like teeth in a jack-o-lantern. But wilderness encroaches from all sides. “My neighbor just saw a little family of coons parading across the street,” said Don Porter, who lives south of Claiborne Avenue, in one of the more occupied areas of the neighborhood. There are four houses on his block, and only two are vacant. “And you see rabbit,” he said. “You see egrets. Pelicans.”

“A raccoon climbs on top of our roof,” said Terry Jacko, 23, who stood with his brother Terrence, 19, in the front yard of their Reynes Street house. “It’s huge. The first time I heard it, I thought it was a dude.”

“I saw a possum in the backyard the other day,” Terrence said. “Its teeth were about this big. I killed it with a stick. It was coming toward me, so I hit him. He just flipped over. I stayed inside after that.”

There have been sightings of armadillos, coyotes, owls, hawks, falcons and even a four-foot alligator, drinking from a leaky fire hydrant. Rats have been less of a problem lately because of the stray cats and the birds of prey. But it’s not just animals that emerge from the weeds. “Sometimes I see people coming out of there,” Terrence said, pointing at the ruins of two houses, shrouded in weeds, across the street. “They’re trying to get in my home.”

Johnny Windsor, who lives with his wife in a rebuilt house nearby that is surrounded on every side by forest, has seen even more disturbing things. “They drag bodies in there,” he said, pointing to a thicket across the street. Bad things have been happening in the abandoned lots. While walking home from school one evening, a 16-year-old girl was dragged into a blighted house and raped. Now Windsor and his wife take turns sitting outside, keeping watch. “You never know,” he said, “if someone’s lying in the grass, ready to shoot.”

For six and a half years, the neighborhood has undergone a reverse colonization — nature reclaiming civilization. Residents have fought with hatchets and weed trimmers to rebuff the colonizers: Southern cut grass, giant ragweed, Chinese tallow trees. But the effort has been largely futile. The lots require constant vigilance. A lot left untended for three months will be thick with knee-high weeds; after five months, saplings begin to rise. By last August, the sixth anniversary of Katrina, it was clear that nature had triumphed.

In September, the mayor of New Orleans, Mitch Landrieu, announced what amounted to a troop surge in the battle for the Lower Ninth. He called it the Nuisance Lot Maintenance Pilot Program. It was the city’s third attempt to clear the overgrown lots in the Lower Ninth. The first contractor chosen for the job was revealed to be a convicted felon; the second contractor, hired a year ago, was asked to clear each lot only once, which was not particularly helpful, because the vegetation grew back within months. This time, the city decided to handle the job itself, using municipal agencies to hire workers and oversee the project. The pilot program consists of a single crew of 12 men — all residents of the Lower Ninth or ex-offenders. They have waged a block-by-block campaign to reclaim the land. The program concludes at the end of this month. At that point the cycle will begin again.

Photo

Credit
Andrew Moore for The New York Times

To understand why New Orleans ceded an entire neighborhood to nature for six years, it’s necessary to revisit a chapter from the post-Katrina era so painful that few in the city have the stomach to discuss it. The Tulane geographer Richard Campanella has called it “the Great Footprint Debate.” With most of New Orleans in ruins, the city had to decide how to rebuild: which areas should receive priority and which should be redeveloped?

The problem, as some saw it, was mathematical. In 1960, the population of New Orleans peaked at 627,525. To accommodate the boom, the city expanded into low-lying marshland that was previously considered unfit for human habitation. These newer, lower-lying neighborhoods were hit hardest by the storm. (The Lower Ninth is higher, on average, than New Orleans East, Gentilly, Broadmoor and Lakeview, but it suffered the most damage because of the two breaches of the Industrial Canal levee, which serves as the neighborhood’s western boundary.) A year after Katrina, the city’s population plunged to about 200,000; meanwhile, the street grid, since 1970, had increased by more than 10 percent. Could a city built for 627,000 maintain a population less than a third of its size? Could taxpayers afford to maintain services like garbage removal, policing, sewer pipes and miles of perpetually eroding streets? And if not, what should be done with the lowest-lying areas and their exiled inhabitants?

A panel commissioned in 2005 by Mayor Ray Nagin, Landrieu’s predecessor, recommended converting large sections of the hardest-hit neighborhoods into “green space.” This activated the survival instinct of local community groups, who saw it as a covert attempt to eradicate the city’s poorest (and blackest) neighborhoods. These suspicions were not allayed by statements like the one made by Joseph Canizaro, a wealthy white property developer who led Nagin’s panel: “As a practical matter, these poor folks don’t have the resources to go back to our city just like they didn’t have the resources to get out of our city. So we won’t get all those folks back.”

Nagin rejected his commission’s recommendations and adopted in its place an approach that most generously might be described as laissez-faire. Residents were allowed to return to the Lower Ninth — which, at 2.25 square miles, is more than four times the size of the French Quarter — as they desired, and the city’s footprint would be preserved. According to the recent census, 5,560 people now live in the area, nearly three-quarters fewer than in 2000. There is currently no police or fire station, supermarket or hospital. Most residents haven’t returned — some because they cannot afford to, others by choice. Between its light population density and lack of basic services, much of the Lower Ninth has fallen into the very condition that New Orleanians after the storm were desperate to avoid: it has become green space.

Landrieu, elected in 2010, has directed considerable amounts of federal and local financing to construction projects in the Lower Ninth. These include $60 million for street repairs, $50 million for rebuilding schools and $14.5 million for a new community center. But clearing the lots is the logical first step. How can you repair a street if you can’t see it?

“The debate about the footprint is history now,” Campanella says. “You can’t reintroduce that question six years later, given that the city, the state and the nation as a whole has already committed recovery dollars to rebuilding houses and fixing utilities. To go back and reopen the wound — it’s too late. The baby’s already born. Maybe next time we could revisit this. I hope there isn’t a next time. But of course there will be.”

When Landrieu took office, New Orleans had the highest percentage of blighted properties of any American city — higher than Cleveland, Flint, Mich., and even Detroit, which, during the last 60 years, has lost 1.1 million people, roughly the population of Dallas. But unlike those of the Rust Belt cities, the population of New Orleans is growing — it is now 356,000 — and its blighted properties have been decreasing. In 2008, one of every three New Orleans properties was uninhabited; today, the number is less than one in four.

Landrieu has emphasized blight reduction and generally spent the government’s money according to his constituents’ wishes. For this he has earned their appreciation; a poll conducted in November gave him an 88 percent favorability rating. “The people of New Orleans, through their elected officials and their advocacy, have decided to rebuild every part of New Orleans,” Landrieu told me. That decision “necessarily put us on a longer course and created a challenge that is hard to achieve, especially with a limited amount of money. But I think that you can, with a lot of good strategy and thought, rebuild neighborhoods. We’re in an exercise now that’s attempting to prove that point.” It remains to be seen what point will be proved by this approach, but Landrieu is not wasting any time. He has promised to complete more than 100 “recovery projects” within four years, or just in time for the next mayoral campaign.

Campanella operates on a different time frame. As a geographer, he has the luxury — or Cassandra’s curse — to contemplate the city’s future three decades, even three centuries from now. The walls of his Tulane office are decorated with giant photographs of New Orleans, the Mississippi River and the United States taken from outerspace.

Few cities have been more acutely influenced by their geographical location than New Orleans, which the geographer Peirce Lewis once called the “inevitable city on an impossible site.” Here, location is destiny; or, more precisely, elevation is destiny. The oldest, wealthiest, whiter, “historic” neighborhoods, where most transplants reside, are on high ground. Most of the newer and poorer neighborhoods, where the greatest concentration of native New Orleanians live, are at, or below, sea level — and sinking. The difference between the French Quarter, which survived Katrina relatively unscathed, and the back section of the Lower Ninth, is nine feet.

Campanella’s geographical history of New Orleans, “Bienville’s Dilemma,” is essential reading for those new to town. Readers often ask him where in the city it is safe to live. “I tell them that the higher the elevation, the closer to the river and the closer to the historic urban core, the less vulnerable you will be,” says Campanella, who is himself a transplant. This is not immediately apparent because the port accents of Brooklyn and New Orleans share the same progenitors. “The population we have now is roughly the population we had a hundred years ago, in the 1910s,” he said. “I would love to see our current population living on higher ground, in neighborhoods teeming with life — people on the streets, walking and taking the streetcar to work, living within proximity of most of their needs. I realize that we cannot go back in history. There are 100-year-old cultural transformations that you can’t just ignore. But that is what I would hope for, to the extent that it’s possible.”

The ruination of the Lower Ninth has attracted geographers and ecologists from around the world, especially those in the burgeoning field of catastrophe studies — a field with a busy future. “It’s a fascinating natural laboratory,” Michael Blum, an ecologist at Tulane, says. “New Orleans in general is an outstanding arena in which to understand basic ecological principles related to disturbance. The Lower Ninth lies at the heart of that.”

Photo

The foundation is all that remains of a house at North Rocheblave and Lamanche.Credit
Andrew Moore for The New York Times

The closest analogy to what happened in the Lower Ninth, Blum says, is a volcanic eruption on the order of Mount St. Helens. The next closest is the tsunami that hit Japan’s northeast coast a year ago. This is what distinguishes the Lower Ninth from the most derelict neighborhoods in cities like Detroit and Cleveland. Katrina was not merely destructive; it brought about a “catastrophic reimagining of the landscape.” As in Japan, a surge of water destroyed most human structures. In much of the neighborhood, nothing remained — neither man, plants nor animals. The ecological term for this is simplification. “In 2007, before rebuilding started, when you went down there, it was like going to an agricultural field,” Blum says. “Literally it was wiped clean.”

What happened over the intervening years has made the Lower Ninth one of the richest ecological case studies in the world. Ecologists hypothesize that, after a catastrophic event, human communities and ecological communities return at the same rate. But this theory has not been tested in real time. Blum is among a coalition of scientists — ecologists, ornithologists, botanists, geographers and sociologists — that is studying the Lower Ninth’s recovery to learn how man, and the environment, will cope with future catastrophes.

In the race between nature and man, nature has jumped out to an early lead. But the pattern of growth has been bizarre. The Lower Ninth has been besieged by a flora feeding frenzy. A chaotic mix of plant species, many of which have never existed on that land, are battling for dominance. Before the area was cleared for plantations in the mid-1700s, the Lower Ninth was divided into three ecosystems, depending on elevation. The riverfront was lined with reeds and brambles; behind that was a dense hardwood forest; and farthest back, where Mary Brock and Pee Wee live, lay a cypress swamp populated by stands of palmettos. Today there are very few species native to the land, other than several kinds of sedge and aquatic grass. Only a handful of palm, live oak, pine and bald cypress trees survived the storm.

A variety of species, some exotic, have moved in, among them crepe myrtle, black willow and golden rain trees laced with vines. The undergrowth is a chaotic mix of weeds as high as basketball hoops and flowering shrubs like lantana, oleander and oxalis. Invasive species have infiltrated the neighborhood from the major avenues, the seeds transported by the flatbed trucks that drive to the city. The plant and animal life varies quixotically from plot to plot, as the new species entrench themselves, mustering strength, before fighting for additional territory.

The ecological composition of the neighborhood may be diverse, but it is also extremely unstable. “It’s a very odd mix, one that you wouldn’t other­wise see in nature,” Blum says. “It’s a Frankenstein community.” Ecologically speaking, Katrina has created a monster.

The 12 men hired to tame this monster meet in the Lower Ninth every morning at 7:30. They wear sunglasses, jeans, boots and bright green city-issued T-shirts. On the back of each shirt is a fleur-de-lis; the front bears the slogan “Fight the Blight.” The Nuisance Lot Maintenance pilot program clears 20 properties a day. When the crew first arrives at a lot, several men tramp through the bramble, dragging to the curb any large pieces of garbage or tires they find. Then comes the tractor, a two-wheel-drive Mahindra 4025, which a crew member drives through the property like a battering ram.

“I haven’t seen any bodies or skeletons,” Enri Jacques, one of the older members of the work crew, said. “Just wild rabbits, coons and garter snakes.” After Jacques lost his home in the storm, he slept on the Claiborne Bridge for four nights. He learned about the pilot-program job from his probation officer. “It beats being incarcerated,” he said. “It was very hard for me to find work. This job is a blessing of Christ. My house is still not totally livable right now, but now that I’m working, I’m able to put a little money aside.”

After the tractor finishes its circuit, two men stroll through the lot waving weed trimmers, the gasoline-powered machines used for residential lawn cutting. They resemble a fencing foil, only the tip culminates in a small mechanical spool that spins roughly a hundred times per second. Weed trimmers are powerful enough to cut most plants and shrubs, but not trees. When Adrian Tillman, a lanky, 28-year-old member of the crew, uses a trimmer, he wraps a black shirt around his head so that the flying debris won’t cut his face.

Tillman did construction work at Jackson Barracks, the military base in the Lower Ninth that is still being repaired. After being laid off, he struggled to find a job until his mother told him that the city was looking for people from the Lower Ninth to cut grass. Since Tillman must constantly cut the grass around his own house, he was prepared for the work. “It’s a laid-back job,” he said, especially because the crew was told to stay clear of any trees or ruined structures. His neighbors thanked him for his work. “When they see us coming,” Tillman said, “they clap their hands.”

A property is crossed off the list once the grasses and weeds are cut and the sidewalk swept clean of debris. To be clear, a “cut” lot does not resemble in the slightest a mowed lawn. The field is often reduced to a pockmarked stubble, bald patches alternating with tussocks of jaggedly shaved 6-inch weeds. In other lots the quantity of vegetation is so great that, when the crew’s work is done, the ground is covered by a heavy carpet of mowed grass. But it doesn’t last long. Plots cleared this December are already sprouting wildflowers a foot high.

Not everyone in the neighborhood has been satisfied with the work of the Nuisance Lot Maintenance pilot program. A Mr. Harris, who declined to give his first name, stood on a viewing platform built on the flood wall at the edge of Bayou Bienvenue. He ate sunflower seeds while three friends, lifelong residents of the Lower Ninth, baited lines for drum and redfish. Harris gestured at a cleared lot near Florida Avenue, at the edge of which stood a pile of construction debris left behind by the crew.

“If we’re going to pay you money to do that, I want professional work,” he said. “Hire some real professionals. I don’t want it to look like that there.”

Photo

A work crew that clears vegetation in the Lower Ninth Ward.Credit
Andrew Moore for The New York Times

Harris spit out his sunflower shells in disgust. A luxury motor coach, filled with tourists behind tinted windows, trundled down Florida Street toward the Make It Right houses. Seventeen expletives have been edited out of the following paragraph:

“Every day 20 tour buses come down this street to look at this neighborhood and take pictures,” Harris said. “Don’t tell me they’re just touring the city. If you’re trying to tour the city, then you’re in the wrong neighborhood. They just ride around in the part that’s been devastated. Lower Ninth Ward ain’t receiving a single penny for that. Why can’t I get something? Why does the man driving the bus get all the money? I ain’t a guinea pig. I don’t want to be put under a microscope. We’re the ones that suffered down here, who lost everything. There are still dead people that they haven’t accounted for. It’s frustrating. It took almost seven years for the Ninth Ward to look like what it looks like now, and it still don’t look like [anything].”

The going rate for a Hurricane Katrina tour of the Lower Ninth Ward is $40. Motor coaches are operated by Big Easy Tours, Historic New Orleans Tours and Gray Line, which offers customers an “eyewitness account of the events surrounding the most devastating natural — and man-made — disaster on American soil!” plus the chance to “drive past an actual levee that ‘breached.’ ”

Tauck, the upscale guided-tour operator, spends one morning in the Lower Ninth as part of its eight-day New Orleans package (from $2,750). The day begins at the Greater Little Zion Baptist Church, which was founded in 1900 and rebuilt a year after the storm. The 42 members of the tour, almost all of whom are white and appear older than 60, sit patiently in the pews, cameras in laps, while a video showing the destruction is projected on the sanctuary. An introductory talk about the horrors of Katrina — the unmarked graves, the toxic mold, the cruel bureaucratic inanities of FEMA — is presented by Laura Paul, a 41-year-old Canadian who came as a volunteer aid worker after Katrina and never left. In her previous life, Paul was a client coordinator for global express aircraft at Bombardier Aerospace outside Montreal. Now she runs lowernine.org, a nonprofit organization whose volunteers rebuild homes, operate an urban farm and collected the data on abandoned lots that was used to develop the Nuisance Lot Maintenance pilot program. Tauck donates $25 per tour participant to lowernine.org.

“The issue with the neighborhood is not the tours themselves,” Paul said, “but the fact that people are making bank on them and not giving anything back to the community. And they can be disrespectful: people get out of the buses, trample private property and take pictures. I really do think that Tauck is doing the right thing. I like the company, I like the tour guides, I like the people they bring to the neighborhood. You’re talking about upper-class, predominantly white people. They have a lot of money.” A woman from a Tauck tour once sent Paul a check for $5,000.

“Getting money after a storm is like shooting fish in a barrel,” Paul added. “But long-term recovery? People just don’t want to know how long it takes. The truth is discouraging. It could easily take another 10 years. We’ll work until we run out of money. The problem is that someday — and this might already be starting — people will be like: ‘Seriously? Enough with the Katrina stuff. Please, just stop.’ ”

The only person on the Tauck bus who seemed truly uncomfortable about the tour was Renee Whitecloud, the tour guide. Whitecloud, who grew up in New Orleans, carries in her wallet a photograph of her flooded street in the Broadmoor neighborhood. By the time she returned home after the floodwaters receded, mold had crept all the way up to the second floor. The mold was “psychedelic,” she said. “Green, orange, yellow, all different colors.” She developed asthma and allergies and suffered frequent migraines. “I love the city,” Whitecloud said, “but this is a hard day for me.” She stood outside the bus while her tourists walked through a house on Caffin Avenue that lowernine.org rebuilt. “It’s in your face,” she said. “Every time I do this tour, I have to revisit the trauma.” When the Katrina video plays in the church, she stands outside.

Because the motor coach is too large to negotiate the broken residential streets, it drives in a rectangle around the most devastated section of the Lower Ninth, sticking to the major thoroughfares. During a tour in October, it drove alongside the Industrial Canal, pausing so that the passengers could see the area where the levee breached. As it slowly passed through the Make It Right houses, a teenage boy ran to the curb, and the driver — whose own house is still gutted from Katrina — pulled over. The door opened and the boy stepped on. The bus filled with the kind of silence that follows a popped balloon. The boy held a carton of homemade pralines.

“Three for $10,” he said. “Buy one for a good cause.”

The 42 members of the tour group sat stiffly in their seats, staring forward in silence.

No one offered the boy any money. After another excruciatingly long pause, he stepped out onto the street. The motor coach scuttled back to the French Quarter.

The Nuisance Lot Maintenance pilot program has now cleared more than 1,200 lots. The transformation of the neighborhood is stark. Ruined houses still tilt like old prizefighters on nearly every street; the roads are chassis-rattling slalom courses; and there are few people, other than tourists, in sight. But no longer are there full blocks of uninterrupted jungle. The worst parts of the neighborhood are desolate but neat. It is uncertain what exactly will happen next to the cleared lots. As Jeff Hebert, the executive director of the New Orleans Redevelopment Authority, said, “Cutting grass once isn’t really a good option.” In the Lower Ninth, a property remains cleared for only three to six months. A Chinese tallow tree, for instance, will grow from seed to two-foot-high sapling in a summer and six feet within a year.

Photo

In New Orleans, elevation is destiny, and the Lower Ninth Ward suffered because of that.Credit
Andrew Moore for The New York Times

When I asked Landrieu what might be done next with the lots, he had no specific answers but emphasized the need for private development. “We don’t know what the end looks like,” he said. “We think we know what the process looks like. We want to get those lots back in the hands of private-property owners so that they can take responsibility for them. Anything we can do to make them attractive to private investors, we want to do.” He acknowledged that, while the city has made significant progress in fighting blight in other poor neighborhoods, the Lower Ninth “has become a symbol of New Orleans’s rebirth, whether that’s justified or not.” Nor is it simply a question of restoring the conditions that existed before the storm. “I keep telling people that we’re not putting things back like it was,” he said. “We’re building the city we want to become.”

Hebert wasn’t any more specific. “All properties will receive a level of maintenance until such time as there is interest in the property for new housing or alternative uses like parks, community gardens, etc.,” he wrote in an e-mail. “It is not the goal of the city to maintain in perpetuity.”

I recently accompanied Peter Yaukey, an ornithologist at the University of New Orleans who has been surveying bird life in the Lower Ninth for six years. On his first visit, a month after the storm, he was not allowed north of Claiborne Avenue because the authorities were still searching for bodies. The first thing he noticed was the silence. When a sound editor from the HBO show “Treme” asked him what type of birds were heard in New Orleans after the storm, Yaukey said there was a nearly complete absence of bird song. The city had no ambient sound. You could hear a boombox from three blocks away.

Many of the birds that used to be common in the Lower Ninth — like mourning doves and house sparrows — had almost entirely disappeared and only now are beginning to return in small numbers. But over the course of several years, as the lots grew thick with weeds and the rodent populations increased, Yaukey observed that something strange was happening. Large predators, which feed on rats and mice, began to appear in high numbers. So high, in fact, that there was soon a much greater concentration of hawks, falcons and shrikes in the Lower Ninth than would be found in a rural environment. He suspected that barn owls were building nests in the blighted buildings. The word Yaukey used to describe the concentration of raptors was “supernatural.” Both senses of the word seemed to apply.

Yaukey, who bears a strong resemblance to the actor Thomas Haden Church and has the same raspy voice, began spotting birds through the windshield as soon as we turned off Claiborne. He wore a pair of binoculars around his neck, but he didn’t need them to identify the birds that glided hundreds of feet overhead: a white ibis, a red-tailed hawk, a turkey vulture and an osprey, clenching in its talons a fish plucked from the Industrial Canal. There were plenty of species at street level as well: blue jays, cardinals, American crows, Eastern phoebes, killdeer, loggerhead shrike, kestrel falcons, bronzed cowbirds and, rarest of all, an open-ground woodpecker. A great egret, regal and stiff, promenaded down the middle of Choctaw, stalking lizards. A flock of roughly 300 European starlings pecked at insects and weed seeds on the Caffin median. An exceedingly plump red-shouldered hawk perched on the bending branch of a mulberry tree. To Yaukey’s amazement, the hawk did not budge even when we came within 10 feet. “It looks pretty tame,” he said. “Almost to the point of being goofy.”

Yaukey was surprised by how substantially the lot-maintenance crew had altered the landscape. He pointed out that the overgrown lots that did remain were rapidly changing. The tall weeds were being crowded out by saplings and trees, especially the aggressive and omnipresent Chinese tallow, whose leaves had begun to turn yellow, crimson and purple. If left alone for another five years, the Chinese tallow might conquer every inch of land in the Lower Ninth, creating a suffocating monoculture, but for the time being, a wide variety of plants thrived in the understory. He was especially eager to find a dense lot that he could explore with the hope of finding birds, like sparrows, that favored brush. He found a suitable spot — three contiguous abandoned lots — at the corner of Jourdan and Law. We were just a few blocks behind Brad Pitt’s houses and across the street from the Industrial Canal levee. It was at this spot, more than six years ago, that four of the concrete slabs cracked, the soil gave way and the inundation of the Lower Ninth began.

Before the car came to a complete stop, Yaukey was out the door, tramping into the weeds. Birds started hopping and darting about. He made birdcalls: pish-pish-spish-spish-SPISH. Wee! Weeweewee! And another that is difficult to transcribe but sounded like a rotating lawn sprinkler.

By the time I locked the car, he was 20 feet away, obscured to his neck by the high weeds. The birds were calling back to him. “Field sparrow,” he marveled, cocking his head. “Swamp sparrow.”

Pish-pish-spish-spish-spish-SPISH.

“I’ve gone whole winters without seeing a field sparrow in the New Orleans vicinity. Field sparrows, swamp sparrows, simply do not winter in residential New Orleans. So this habitat . . .,” he trailed off. “I can come here and see them.” The excitement was high in his voice.

It was difficult to keep up — he had the bounding energy of a child let out to recess. The brush was so dense that it was impossible to find secure footing. Every step cracked a branch. Thorns tugged on pants. Cordlike vines noosed around ankles like booby traps. I kicked a concrete slab, concealed beneath a mound of dirt — the foundation of the house that once stood there.

“Rattlebox!” Yaukey said, pointing to an invasive South American tree he spotted in the middle of a thicket. Clusters of dark brown pods dangled like earrings from its stalks. Only a sandy tuft of Yaukey’s hair was visible now. His voice was hard to make out, and I had to ask him to repeat himself.

“Orange-crowned warbler!” he shouted back at me. “Ruby-crowned kinglet!”

Finally I gave up. Yaukey was too deep in the woods. It was no longer possible to distinguish which calls were his and which the birds’. He walked around a stand of 15-foot Chinese tallow trees, the green and crimson leaves waving mournfully in the wind. And then he was gone. The wilderness just swallowed him up.

Correction: April 8, 2012

An article on March 25 about the Lower Ninth Ward of New Orleans since Hurricane Katrina misspelled the given name of a geographer who called New Orleans ‘‘the inevitable city on the an impossible site.’’ He is Peirce Lewis, not Pierce.